Los Angeles County urban planners have been charged with investigating what kinds of authority that county officials may have to regulate "maternity hotels" that cater to women from other countries who travel to the United States in order to obtain American citizenship for their babies.

"We have seen a rise in the number of neighbors calling in complaints on maternity homes," Supervisor Don Knabe said. "More importantly, it's a safety issue. Are they getting proper medical treatment? Are they undocumented?"

"Maternity tourism" is a semi-underground business in Southern California and other parts of the country. The recent discovery of an alleged maternity hotel in Chino Hills in San Bernardino County has brought renewed attention to the phenomenon.

In the letter of current immigration laws, maternity tourism is a legal method for often-wealthy families to seek American citizenship for their children, and the practice is reported to be gaining popularity in countries including China, South Korea and Turkey.

Even so, immigration conservatives tend to object to the idea of granting birthright citizenship to an infant who may spend little - if any - of his or her childhood in the United States.

The Supreme Court, however, affirmed the 14th Amendment in 1898. More recent attempts to modify citizenship law have stalled in Congress.

Local governments have attempted to address maternity hotels as a code enforcement or zoning matter. The controversial enterprises are said to frequently exist in residential areas where no hotels of any kind would be allowed.

Chino Hills authorities have filed a public nuisance complaint against an alleged maternity hotel in that city.

In Los Angeles County, the city of San Gabriel in 2011 used its code enforcement authority to shutter a cluster of townhomes used as a maternity hotel on the grounds the buildings were unsafe.

Knabe said his office has received several complaints of alleged maternity hotels in eastern San Gabriel Valley communities such as Rowland Heights, Hacienda Heights and La Puente.

The supervisor said his personal preference would be to shut down maternity hotels.

Knabe recently carried a motion calling for Los Angeles County officials to return a report to the Board of Supervisors by mid-January about what kind of authority county government has to deal with maternity hotels.